//
//  NSString+GXMD5.m
//  24-加密
//
//  Created by Snow on 16/8/16.
//  Copyright © 2016年 Snow. All rights reserved.
//

#import "NSString+GXMD5.h"
#import <CommonCrypto/CommonCrypto.h>
@implementation NSString (GXMD5)
//字符串转换 32位 MD5 小写和大写
- (NSString *)stringWith32BitMD5
{
    //1.将字符串转换成C语言字符串
   const char *cString = [self UTF8String];
    CC_LONG length = (CC_LONG)strlen(cString);
//    CC_MD5_DIGEST_LENGTH
    unsigned char bytes[CC_MD5_DIGEST_LENGTH];
    //2.将C的字符串转换 MD5
    CC_MD5(cString, length, bytes);
    //3.将C的字符串转换成OC的字符串
    NSMutableString *finalMD5String = [NSMutableString stringWithCapacity:CC_MD5_DIGEST_LENGTH * 2];
    for (int i = 0; i < CC_MD5_DIGEST_LENGTH; i++) {
        [finalMD5String appendFormat:@"%02x", bytes[i]];
    }
    return finalMD5String;
}
- (NSString *)stringWith32BitMD5Lower
{
    return [[self stringWith32BitMD5] lowercaseString];
}
- (NSString *)stringWith32BitMD5Upper
{
    return [[self stringWith32BitMD5] uppercaseString];
}
- (NSString *)stringWith16BitMD5
{
    NSString *string = [self stringWith32BitMD5];
    NSString *str = [string substringFromIndex:8];
    return [str substringToIndex:str.length - 8];
}

- (NSString *)stringWith16BitMD5Lower
{
    return  [[self stringWith16BitMD5] lowercaseString];
}

- (NSString *)stringWith16BitMD5Upper
{
return [[self stringWith16BitMD5] uppercaseString];
}

@end
